Rep Power: 0

not sure what the problem is but,,, i recently upgraded my stock wheels n tires too

15" inch Falken ziex 60/195 mounted on 2000 SIR wheels

everything is fine...i love the handling BUT,....when i go over 150 on the highway it starts vibrating a bit...i took it back to sears..because they did all the mounting to begin with. So they basically switched all the tires around (rotated them) and now the shake is comming from the back wheels...and not the front...ive chekced the wheels and they are TRUE. no bends or damage or curbs whatsoever...the wheels are all torqued down properly...im not sure whats causing this...and the alignment is perfect! it started happening once i changed from my stock wheels/tires to these... do i need hubcentric rings or something? someone plz help me!!!!

 
Rep Power: 0

?! did they check the balance again? and 150 on the highway? you go pretty fast!

 
Rep Power: 328

sounds like a balance or tire out of round issue

 
Rep Power: 388

^^I agree

 
Rep Power: 0

yeah they checked the balance also...still not sure whats makin it vibrate
and yah..150 km\hr so thats like 90mph... thats not that fast.

 
Rep Power: 812

Same thing happens to me. You need to get a wheel ALIGNMENT. It's different from balancing the tires. Basically it's to make sure the wheels are parallel with the car. I'm waiting until spring when I get new tires to do it.

 
Rep Power: 375

^^^^^^Yup that will fix it.

 
Rep Power: 328

wheel alignment doesn't follow tire rotation its not the alignment, you have either a tire out of balance, bent wheel, or out of round tire. Not to mention VIBRATION is caused from something out of balance, out of round, or no loger at a 90` to the axis( bent wheel ) Wheel alignment can NOT cause vibration, well not direct anyways.